Temporal and spatial assessment of gaseous elemental mercury concentrations and emissions at contaminated sites using active and passive measurements

Abstract Gaseous elemental mercury (GEM) concentrations and emissions at legacy contaminated sites represent poorly characterised components of global (Hg) inventories. Here we apply both active (Tekran 2537A) passive (MerPAS) sampling methods to comprehensively assess GEM across four dimensions (three spatial, one temporal) a site with elevated soil Hg. Concentrations are measured up 37.4 (active) 10.8 (passive) ng m ?3 , which represents enhancements 23× 7× above background (1.62 ), respectively. Temporal resolution the defines this difference (active: 5-min; passive: 44 days). Diurnal concentration patterns were highest in areas night when low wind speeds compress boundary layer. Passive substantially improves spatial characterisation horizontally (highest Hg) vertically (improved vertical gradient using telescopic towers). sampler deployments used generate estimate (landfill-to-atmosphere) 1.2 ± 0.6 kg yr ?1 (or 310 150 ?2 h ). This study demonstrates how combining (strength: temporal assessment) assessments) evaluation atmosphere Hg dimensions.